Washington is debating restricting guns or improving mental health care to reduce the number of shootings in America, but the clearest predictor of gun violence has gotten less attention: poverty.

State-level data surveys show poverty as a bigger risk factor for gun violence than a citizenry with unrestricted access to guns. And while new gun laws might make it harder for those with criminal intent to get their hands on deadly weapons, alleviating poverty could stop criminal behavior before it starts.

In a 2011 state-by-state analysis by researchers at the Martin Prosperity Institute, poverty was more highly correlated with gun deaths than almost any other state characteristic, including the percentage of students who carry weapons to school. The association was stronger than that between assault weapons bans and lower gun deaths.

Common recommendations for curbing gun violence, meanwhile, have key limitations. More intensive interventions for mental illness might not have much effect on the overall gun violence rate, given that severely mentally ill people are involved in only about 4% of violent crime. And while assault weapons bans are associated with fewer gun deaths at the state level, the majority of murders aren't committed with assault weapons.

Chicago

Conservatives like to point to Chicago — with a brutal epidemic of homicides despite tight gun laws — to show gun control can't work. Others argue those laws don't carry stiff enough penalties.

But in fact Chicago offers one of the clearest connections between poverty and gun violence. Last year, Chicago Reader reporter Steve Bogira compared homicide rates in the city's five poorest neighborhoods with those in its five least poor.

His finding: The average rate of gun deaths in Chicago's five poorest neighborhoods was over 12 times the rate in its least poverty-stricken.

There's even compelling evidence that growing up poor makes an individual person more likely to commit violence. A team led by researchers from the University of Pittsburgh School of Medicine followed boys randomly selected from Pittsburgh public schools from 1987 to 2003 and tracked whether the boys committed violent crimes. They developed an 11-factor model for predicting whether a given boy would become violent. Some of the factors were related to the boys' psychological and emotional development, things like depression and a history of callous or unemotional behavior. But three factors related directly to poverty: low socioeconomic status, being on welfare, and living in what their parents reported was a "bad neighborhood." Another, high parental stress, may be indirectly related, since poverty has been shown to increase stress.

The model was effective at predicting violence — boys with four or more of the risk factors were six times as likely to become violent as boys with fewer than four. The team also created a separate but similar model specifically for predicting homicide. It was even stronger than the violence prediction model — boys who had four or more homicide risk factors were 14 times as likely to commit homicide as boys with less than four.

"The implication," the authors explain, "is that violence-producing processes more often accumulate over many years rather than suddenly emerging." Poverty appears to be one such process — reducing it might keep kids from seeking out guns in the first place.

We're also at a point in history where a disturbingly high percentage of children are living in poverty — 21.9% in 2011. If we want to keep them from growing up to kill or be killed, their economic well-being may be the most powerful place to start.